Jafar Panahi is also barred from making films for 20 years, his lawyer says. He was accused of making an unauthorized movie about the protest movement in Iran.

Reporting from Beirut — A celebrated Iranian filmmaker and opposition supporter has been sentenced to six years in prison and barred from making films or participating in political activity for two decades, his lawyer said Monday.

Jafar Panahi, 50, is the director of internationally renowned Iranian art films such as "The Circle" and "Crimson Gold," which delved into Iran's complex social problems. He was a supporter of the protest movement that sprang to life after the disputed 2009 reelection of President Mahmoud Ahmadinejad. He was arrested in March on charges of conspiring to make an unauthorized movie that chronicled the movement and released on bail 12 weeks later pending his sentencing.

His lawyer, Farideh Gheirat, told the semiofficial Iranian Students News Agency that the Revolutionary Court had handed Panahi the six-year sentence and barred him from writing screenplays or traveling abroad for 20 years. Gheirat said the sentence was disclosed Saturday.

Another director, Mohammad Rasoulof, who allegedly was collaborating with Panahi on the unfinished movie, was also sentenced to six years in prison, his lawyer told the news agency. The lawyer vowed to appeal the verdict.

The filmmakers were convicted of national security violations, including propagandizing against the system, a charge often lodged against journalists and artists critical of the hard-line government.

Since the protests last year, security forces have intensified a crackdown on the country's once-lively civil society and its once-powerful reform movement, which hard-liners regularly describe as part of a Western-backed plot to topple the Islamic Republic.